From the discussion forum on energy intensity of batteries:

XHH: And what command do I need to enroll to activate an additional charge? Well, for example: the phone has discharged, and the charging with you or no access to the network. Somewhere I heard that you can type some combination of numbers on the phone so that it is half charged)
zzz: it's like if you've gotten out of gasoline and you've gotten the wheels in a certain sequence, then you'll have a half tank of gasoline)))